Problematic

You may need to access some files, such as a SSH key, from your application hosted on Scalingo. Committing these files on your Git repository is not a good security practice. This page guide you through the steps to securely share that kind of secret files with your application.

Access Secret File From the Application

Let’s say you want the file private.pem to be available in your application. You first need to set it in base64 as environment variable of your application:

scalingo --app my-app env-set SECRET_FILE=$(base64 -w 0 ./private.pem)

Then you need to modify the way your application starts so that it first write the content of the environment variable SECRET_FILE to the disk then effectively start the application.

Update (or add) a Procfile to define the web container:

web: ./bin/start-app.sh

And create the script bin/start-app.sh with the following content:

#!/bin/bash

echo $SECRET_FILE | base64 -d > ./private.pem
# Start default script for PHP apps
$HOME/bin/run

Commit both files and deploy your application. Your application has now access to your secret file in /app/private.pem!

Note that the file /app/private.pem is not available in a one-off container. This solution makes it available when booting the web container. Hence the file is only available in web containers and not one-off containers.